AUTOMATIC SHEET LOADER

Abstract: An automatic sheet loader for automatically carrying sheets to a cardboard packer comprising at least a pair of chains (35) extended between an upper sprocket (33) and a lower sprocket (34) in such a manner as to confront the sprockets, respectively, so as to form a sheet carrying path (32) therebetween, brackets (36) fixed to said chains (35) at set intervals in such a manner as to protrude therefrom towards said sheet carrying path (32) so as to support a group of sheets from both sides and driving means for driving said chains (35) and moving said brackets (36) downwardly along said sheet carrying path (32) to thereby carry said group of sheets, wherein sheets to be set are changed when the dimensions of each wrapping container of a group of wrapping containers, the number of wrapping containers in said group of wrapping containers, or form of wrapping are changed, however, since each group of sheets are moved vertically downwardly by means of said chains (35) so as to be carried, when changing groups of sheets, it is easy to distinguish a group of sheets used from a group of sheets to be used next.

Description: TECHNICAL FIELD The present invention relates to an automatic sheet loader. BACKGROUND ART Conventionally, packaging containers which are unloaded from a filling machine after being filled with a liquid food or the like are transferred to a cardboard packer in which a predetermined number of packaging containers are stacked in a packing pattern and placed in a case made of a sheet. The case is produced by folding a blank sheet formed by cutting a corrugated cardboard, a cardboard, or the like into a predetermined shape by a die cutter. The shape of the blank sheet varies in accordance with the dimension and number of packaging containers to be placed in the case, and the manner of packaging. In the case of a tray sheet, the sheet has a shape to cover two opposing side surfaces of a group of packaging containers which have been stacked on the sheet in a predetermined packing pattern. In the case of a carrier sheet, the sheet has a shape to form grips for transportation as well as to cover two opposing side surfaces of a group of packaging containers which have been stacked on the sheet in a predetermined packing pattern. In the case of a wrap-around sheet, the sheet has a shape to wholly cover a group of packaging containers which have been stacked on the sheet in a predetermined packing pattern. The cardboard packer is provided with a magazine slanted at about 45°. For example, 50 sheets are bundled to form a group of sheets, and the group of sheets is manually set into the magazine. The cardboard packer is also provided with a suction device which takes out a single sheet at a time from the magazine by a suction force, and places it on a table of the machine. Subsequently, a group of packaging containers which have been conveyed by a conveyer is placed on the sheet, and is wrapped by folding the sheet by a folding machine. Since the group of sheets is placed in the magazine which is inclined at 45°, the load imposed on the bottom sheet can be reduced, thereby facilitating the taking out of the sheets by the suction device. However, the conventional cardboard packer requires a cumbersome work because the group of sheets must be manually set into the magazine. Moreover, in the case where the group of sheets set into the magazine is replaced with a different group of sheets because of changes in the dimension or number of packaging containers in the group or the manner of packaging, it is necessary to watch the operation to prevent the previous group of sheets and the new group of sheets from being used in mixture. An object of the present invention is to solve the problems involved in the conventional cardboard packer, and to provide an automatic sheet loader which can automatically set a group of sheets into a cardboard packer, and can easily replace the group of sheets when the dimension or number of packaging containers to be packed, or the manner of packaging is changed. DISCLOSURE OF THE INVENTION To achieve the above-described object, an automatic sheet loader according to the present invention is provided with a sheet transfer path along which a group of sheets is transferred downwards, a swinger which is pivotably supported at the lowermost end of the sheet transfer path, and which receives the group of sheets at a horizontal position and then pivots toward a magazine section to take an oblique position, drive means for swinging the swinger, a magazine which is disposed slanted and into which the group of sheets dropped from the swinger is set, and a suction device for taking out each sheet of the group from the magazine by a suction force. The swinger has a stopper for temporarily holding the group of sheets. In a preferred embodiment of the present invention, the stopper is swingably supported by the swinger via a shaft, and takes a hold position for holding a group of sheets and a release position for releasing and dropping the group of sheets. In another preferred embodiment of the present invention, the stopper is provided with a pair of taper keys having opposing slant surfaces. The stopper is fixed on the shaft by moving the taper keys relative to each other. In still another preferred embodiment of the present invention, the automatic sheet loader is provided with sheet transfer means, disposed in the sheet transfer path, which includes at least a pair of chains disposed between upper sprockets and lower sprockets so that the pair of chains face each other to form a sheet transfer path therebetween, brackets mounted on the chains at predetermined intervals and projecting toward the sheet transfer path for supporting a group of sheets from both sides thereof, and drive means for running the chains so as to move the brackets along the sheet transfer path for transferring the group of sheets. In yet another preferred embodiment of the present invention, the automatic sheet loader is provided with a width adjusting mechanism for moving the chains in accordance with the dimension of the group of sheets. As described above, the automatic sheet loader according to the present invention is provided with a sheet transfer path along which a group of sheets is transferred downwards, a swinger which is pivotably supported at the lowermost end of the sheet transfer path, and which receives a group of sheets at a horizontal position and then pivots toward a magazine section to take an oblique position, drive means for swinging the swinger, a magazine which is disposed slanted and into which the group of sheets dropped from the swinger is set, and a suction device for taking out each sheet of the group from the magazine by a suction force. The group of sheets transferred along the sheet transfer path is received by the swinger at the lowermost end of the sheet transfer path. The swinger has a stopper for holding and releasing the group of sheets. The swinger supports the group of sheets transferred along the sheet transfer path. Subsequently, the swinger is swung to the oblique position at which the group of sheets is released from the swinger and is set into the magazine. The suction device takes out one sheet at a time from the magazine by a suction force and puts it on the table of the machine. In a preferred embodiment of the present invention, the stopper is swingably supported by the swinger via a shaft, and takes a hold position for holding a group of sheets and a release position for releasing and dropping the group of sheets. Accordingly, the group of sheets is received when the stopper is located at the hold position and is released when the stopper is moved to the release position. In another preferred embodiment of the present invention, the stopper is provided with a pair of taper keys having opposing slant surfaces. When the taper keys are moved relative to each other, the stopper is fixed to the shaft due to a wedge effect. In still another preferred embodiment of the present invention, the automatic sheet loader includes at least a pair of chains disposed between upper sprockets and lower sprockets so that the pair of chains face each other to form a sheet transfer path therebetween, brackets mounted on the chains at predetermined intervals and projecting toward the sheet transfer path for supporting a group of sheets from both sides thereof, and drive means for running the chains so as to move the brackets along the sheet transfer path for transferring the group of sheets. When the operation of the drive means is started, the chains are run so that the group of sheets held between a pair of brackets is transferred from an upper side to a lower side. The brackets are turned at the lowermost end of the sheet transfer path to release the group of sheets. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front view of an automatic sheet loader showing an embodiment of the present invention; FIG. 2 is a perspective view of the automatic sheet loader showing the embodiment of the present invention; FIG. 3 is a perspective view of a group of tray sheets; FIG. 4 is a perspective view of a group of carrier sheets; FIG. 5 is a perspective view of a group of wrap-around sheets; FIG. 6 is a plan view of the automatic sheet loader showing the embodiment of the present invention; FIG. 7 is a front view of a lifter used in the embodiment of the present invention; FIG. 8 is a plan view of the lifter used in the embodiment of the present invention; FIG. 9 is a detailed view of a chain unit used in the embodiment of the present invention; FIG. 10 is a side view of the lifter used it, the embodiment of the present invention; FIG. 11 is a detailed view of a main portion of a swinger used in the embodiment of the present invention; FIG. 12 is a perspective view of the swinger used in the embodiment of the present invention; FIG. 13 is a perspective view of a lower member of the swinger used in the embodiment of the present invention; FIG. 14 is a perspective view of an upper member of the swinger used in the embodiment of the present invention; FIG. 15 shows perspective views of second stoppers used in the embodiment of the present invention; and FIG. 16 is a perspective view of a main portion of the second stopper used in the embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will now be described with reference to the accompanying drawings. FIG. 2 is a perspective view of the automatic sheet loader showing the embodiment of the present invention, FIG. 3 is a perspective view of a group of tray sheets, FIG. 4 is a perspective view of a group of carrier sheets, and FIG. 5 is a perspective view of a group of wrap-around sheets. In FIG. 2, numeral 11 denotes an automatic sheet loader provided with a lifter 12. In the lifter 12, a group of sheets 14 formed by bundling a predetermined number of sheets is transferred downwardly. The group of sheets 14 is transferred in the lifter 12 while being horizontally supported, and reaches a swinger 15 disposed at the lowermost portion of the lifter 12. The swinger 15 is swingably supported to take a horizontal position for horizontally supporting the group of sheets 14 and an oblique position for supporting the group of sheets 14 slanted at about 45°, When the swinger 15 located at the horizontal position receives a group of sheets 4 which have been transferred, the swinger 15 swings toward the magazine section 17, and is placed at the oblique position to set the group of sheets 14 into an unillustrated magazine. On the other hand, a group of packaging containers conveyed by an unillustrated conveyer is supplied to an infeed section 18, and is pushed by an unillustrated pusher disposed at a proper position in the infeed section 18 so that a predetermined number of packaging containers are stacked in a predetermined pattern. In a cardboard packer 20, a suction device takes out one sheet at a time from the magazine by a suction force, and places it on a table of the machine. The sheet is then folded by an unillustrated folding device to wrap the group of packaging containers. Numeral 11a denotes a frame. The group of sheets 14 is formed by bundling 50 sheets, for example. The shape of each sheet varies in accordance with the dimension and number of packaging containers to be stacked, and the manner of packaging. That is, in the case of tray sheets 22 shown in FIG. 3, each sheet has a shape to cover two opposing side surfaces of a group of packaging containers which have been stacked on the sheet 22 in a predetermined packing pattern. In the case of carrier sheets 23 shown in FIG. 4, each sheet has a shape to form grips 23a for transportation as well as to cover two opposing side surfaces of a group of packaging containers which have been stacked on the sheet 23 in a predetermined packing pattern. In the case of wrap-around sheets 24 shown in FIG. 5, each sheet has a shape to wholly cover a group of packaging containers which have been stacked on the sheet 24 in a predetermined packing pattern. Next, the lifter 12 will be described. FIG. 1 is a front view of the automatic sheet loader showing the embodiment of the present invention, FIG. 6 is a plan view of the automatic sheet loader showing the embodiment of the present invention, FIG. 7 is a front view of the lifter used in the embodiment of the present invention, FIG. 8 is a plan view of the lifter used in the embodiment of the present invention, and FIG. 9 is a detailed view of a chain unit used in the embodiment of the present invention. As shown in these drawings, the lifter 12 is disposed above the magazine section 17 and the infeed section 18 of the automatic sheet loader 11. The lifter 12 is composed of a pair of chain units 31a and 31b which form a sheet transfer path 32 therebetween. The chain units 31a and 31b are disposed in the frame 11a of the automatic sheet loader 11 to be parallel with each other and face each other. A pair of guide bars 11b are attached to the frame 11a at predetermined upper and lower positions, respectively. The chain units 31a and 31b have guide rollers 40 which move along the guide bars 11b while rotating. Also, width adjusting units 42 are provided for positioning the chain units 31a and 31b along the guide bar 11b. As shown in FIG. 9, each of the width adjusting units 42 is composed of a bearing 42a fixed on the frame 11a, a ball screw 42b rotatably supported by the bearing 42a, a ball nut 42c fixed between a pair of columns 43 of the chain units 31a and 31b, and a width adjusting sprocket 42d fixed to one end of the ball screw 42b. The width adjusting sprocket 42d is connected to an unillustrated width adjusting motor via an unillustrated chain. Accordingly, the chain units 31a and 31b can be moved in accordance with the dimension of the group of sheets 14 by driving the width adjusting motor which rotates the ball screw 42b. As shown in FIG. 8, each of the chain units 31a and 31b is provided with a pair of chains 35 which are disposed to extend between drive-side upper sprockets 33 and slave-side lower sprockets 34. Brackets 36 are fixed to the chains 35 at a predetermined intervals. Each pair of brackets 36 are fixed to the chains 35 of the chain units 31a and 31b at the same longitudinal position so that the brackets 36 are opposed to each other and projected to the sheet transfer path 32, thereby supporting the group of sheets 14 from both sides thereof. The chains 35 can be run by driving the lifter drive motor 16 which rotates the upper sprockets 33. In detail, rotation of the lifter drive motor 16 is transmitted to a lifter drive shaft 48 via a sprocket 45, a chain 46, and a sprocket 47. The rotation of the lifter drive shaft 48 is then transmitted to the sprocket shaft 49 via an unillustrated bevel gear so as to rotate the upper sprockets 33. When the chains 35 are thus run, the brackets 36 downwardly moves along the sheet transfer path 32, thereby moving the group of sheets 14 downward. When the brackets 36 reach a position at which the chains 35 engage the lower sprockets 34, the brackets 35 move outside along the lower sprockets 34 while turning, and then moved upward. At this time, the group of sheets 14 supported by a pair of brackets 36 on the chains 35 of the chain units 31a and 31b falls from the brackets 36 because the pair of brackets simultaneously turns outside. The group of sheets 14 are then supported by a shooter 51 disposed under the chain units 31a and 31b. The shooter 51 is composed of a pair of first stoppers 51a projecting toward the sheet transfer path 32 like the brackets 36, arms 51b which rotatably support the first stoppers 51a, and swing cylinders 51d for swinging the arms 51b about shafts 51c. Accordingly, the arms 51b are rotated by the swing cylinders 51d to bring the first stoppers 51a in a horizontal posture for supporting the group of sheets 14 and to bring the first stoppers 51a in a vertical posture for dropping the group of sheets 14 on the swinger 15 (see FIG. 2). Next, the swinger 15 will be described. FIG. 10 is a side view of the lifter used in the embodiment of the present invention, FIG. 11 is a detailed view of a main portion of the swinger used in the embodiment of the present invention, FIG. 12 is a perspective view of the swinger used in the embodiment of the present invention, FIG. 13 is a perspective view of a lower member of the swinger used in the embodiment of the present invention, FIG. 14 is a perspective view of an upper member of the swinger used in the embodiment of the present invention, FIG. 15 shows perspective views of a second stopper used in the embodiment of the present invention, and FIG. 16 is a perspective view of a main portion of the second stopper used in the embodiment of the present invention. In FIG. 15, section (a) shows the inner side of the second stopper while section (b) shows the outer side of the second stopper. In these drawings, numeral 15 denotes a swinger which is supported for swing movement about a pivot 53. The swinger 15 takes a horizontal position H for horizontally supporting the group of sheets 14 (see FIG. 8) dropped from the shooter 51 and an oblique position S for supporting the group of sheets 14 in an inclined posture of about 45° . When the swinger 15 receives the group of sheets 14 dropped from the shooter 51 at the horizontal position H, the swinger 15 swings toward the magazine section 17, and positioned at the oblique position S. Also, a swinger drive motor 55 is disposed for swinging the swinger 15. The swinger drive motor 55 is fixed on the frame 11a, and rotates a take-up drum 55a in the forward and reverse directions. One end of a wire rope 57 is fixed to the take-up drum 55a, while the other end of the wire rope 57 is fixed to the forward end of the swinger 15. Accordingly, when the wire rope 57 is wound up, the swinger 15 is brought in the horizontal position H, and when the wire rope 57 is released, the swinger 15 is brought in the oblique position S. A side guide 56 is provided at the forward end of the swinger 15 for preventing the group of sheets 14 from falling down during swing movement of the swinger 15. After the swinger 15 has received the group of sheets 14 dropped from the shooter 51, the swinger 15 holds the group of sheets 14 until it has swung to be positioned at the magazine section 17. At the magazine section 17, the swinger 15 drops the group of sheets 14 to set them into the magazine 17a. The magazine 17a is mounted inclined at about 45° so that the group of sheets 14 dropped from the swinger 15 are held in a slanted state. Moreover, a suction device 59 is arranged underneath the magazine 17a for swing movement about a shaft 59a. The suction device 59 takes out one sheet at a time from the magazine 17a by a suction force. The swinger 15 is composed of a lower member 61 and an upper member 62 which form a sheet group receiving space 63 therebetween for receiving a group of sheets 14. As shown in FIG. 13, the lower member 61 has a pair of side plates 64 which are disposed in parallel and facing each other. Both ends of the side plates 64 are supported by the rods 65. The rods 65 penetrate support members 67 disposed at both ends of the side plates 64, and shafts 69 disposed along the side plates 64 also penetrate both the support members 67. In each of the support members 67, a worm gear and a worm wheel (both not illustrated) are disposed so that when the shaft 69 is rotated by an unillustrated drive motor, the rods 65 are rotated. Since ball screw mechanisms are provided between the rods 65 and the support members 67, the side plates 64 can be moved along the rods 65 by rotating the rods 65. Accordingly, the distance between the side plates 64 can be changed in accordance with the width of the group of sheets 14. As shown in FIG. 14, the upper member 62 has a pair of side bars 70 which are disposed in parallel with each other and face each other. One end of each side bar 70 is supported by a lateral bar 71. Fixing members 74 are projected from both ends of each side bar 70. The upper member 62 is assembled with the lower member 61 such that the support members 67 are covered by the fixing members 74. The lower member 61 and the upper member 62 are integrated with each other by inserting the rods 65 into the through holes 74a formed in the fixing members 74. To form the pivot 53, support members 76 are attached to the frame 11a to support the rods 65 projecting from the fixing members 74. With this structure, the swinger 15 is swingably supported. Moreover, side rods 72 are rotatably disposed on the side bars 70 in parallel with the side bars 70. A ball screw 72a is formed on one end of each side rod 72. Ball nuts 78 are also disposed to be engaged with the ball screws 72a. An adjusting bar 79 fixed to each of the ball nuts 78 is extended toward opposite one of the side rods 72 and is slidably engaged with the opposite side rod 72. Accordingly, when the side rods 72 are rotated by an unillustrated drive motor, the ball screws 72a are rotated so that the adjusting bars 79 are moved. With this operation, the adjusting bars can be moved in accordance with the length of the group of sheets 14. When the swinger 15 receives the group of sheets 14 dropped from the shooter 51, the swinger 15 swings toward the magazine section 17. During this swing movement, the swinger 15 holds the group of sheets 14. For this purpose, a second stopper 80 is provided at the lower end of each of the side plates 64. The second stopper 80 is fixed to a shaft 81, and is supported by the support members 67 via the shaft 81. Each second stopper 80 is positioned at a hold position for holding the group of sheets 14 and at a release position for releasing and dropping the group of sheets 14. As shown in FIG. 15, each of the second stoppers 80 is composed of a side wall 80a extending in the longitudinal direction of the swinger 15, and projection members 80b formed at a plurality of positions along the lower edge of the side wall 80a. The projection members 80b extend perpendicularly with respect to the side wall 80a. When the second stoppers 80 are located at the hold positions, the projection members 80b are projected from the lower ends of the side plates 64 toward the inside of the sheet group receiving space 63. When the second stoppers 80 are located at the release positions, the projection members 80b are retracted to the outside of the side plates 64. For this purpose, a lever 82 is fixed to one end of each shaft 81, and a cylinder 91 is disposed at one end of the corresponding side plate 64. When the piston rod 92 of the cylinder 91 is moved up and down, the lever 82 swings via an unillustrated linkage mechanism. To fix the second stoppers 80 to the shafts 81, ear-shaped projections 83 are formed at the plurality of positions on the outer surface of each side wall 80a. As shown in FIG. 16, each projection 83 has a main portion 83a, and a support portion 83b which extends under the projection member 80b. A through hole 83c is formed in each projection 83 at a location corresponding to the shaft 81, and the shaft 81 penetrates the through hole 83c. Moreover, first and second taper keys 85 and 86 are disposed on each main portion 83a, and the upper surface of the second taper key 86 is contacted with the lower surface of the shaft 81. The first and second taper keys 85 and 86 have opposing slant surfaces. Accordingly, when the relative position between the first and second taper keys 85 and 86 is varied by an adjusting bolt 88, the second taper key 86 is raised and pressed against the lower surface of the shaft 81. In this manner, each second stopper 80 can be fixed to the corresponding shaft 81 by a wedge effect of the first and second taper keys 85 and 86. The lower surface of each shaft 81 is cut away at positions corresponding to each second taper key 86. Even if each projection 83 is made of a soft material such as aluminum, the durability can be increased because the force from each adjusting bolt 88 is small. Further, since the position of each adjusting bolt 88 in the thrust direction can be finely adjusted, the force generated in the radial direction can be made constant. Moreover, since the second taper key 86 is raised by the first taper key 85, it is possible to prevent the adjusting bolt 88 from getting loose by the elasticity of the first and second taper keys 85 and 86. Additionally, a nut may be attached to the end of the adjusting bolt 88 for preventing the bolt 88 from getting loose. The present invention is not limited to the above-described embodiments. Numerous modifications and variations of the present invention are possible in light of the scope of the present invention as defined in the claims. INDUSTRIAL APPLICABILITY The present invention can be applied to an automatic sheet loader for automatically transferring sheets for wrapping packaging containers to a cardboard packer.

Claims: An automatic sheet loader comprising: (a) a sheet transfer path (32) along which a group of sheets (14) is transferred; (b) a swinger (15) which is swingably supported at the lowermost end of said sheet transfer path, and which receives said group of sheets at a horizontal position and then pivots toward a magazine section (17) take an oblique position; (c) drive means (55) swinging the swinger; (d) a magazine (17a) which is disposed slanted in said magazine section and into which the group of sheets dropped from the swinger is set; and (e) a suction device (59) for taking out each sheet of the group from the magazine by a suction force, (f) wherein said swinger is provided with a stopper (80) for temporarily holding said group of sheets. An automatic sheet loader as claimed in claim 1, wherein said stopper (80) is swingably supported by the swinger via a shaft (81), and takes a hold position for holding a group of sheets and a release position for releasing and dropping the group of sheets. An automatic sheet loader as claimed in claim 1 or 2, wherein said stopper (80) is fixed to the shaft (81) by relatively moving a pair of taper keys (85, 86) having opposing slant surfaces. An automatic sheet loader as claimed in one of the preceding claims, further comprising sheet transfer means disposed in said sheet transfer path (32), comprising: (a) at least a pair of chains (35)disposed between upper sprockets (33) and lower sprockets (34) so that said pair of chains face each other to form a sheet transfer path (32) therebetween; (b) brackets (36) mounted on said chains at predetermined intervals and projecting toward said sheet transfer path for supporting a group of sheets from both sides thereof; and (c) drive means (16) for running said chains so as to move the brackets along said sheet transfer path for transferring said group of sheets. An automatic sheet loader as claimed in claim 4, further comprising a width adjusting mechanism (42) for moving the chains in accordance with the dimension of the group of sheets.

Inventors: KANEKO YUTAKA, KANEKO, YUTAKA
Applicants: TETRA LAVAL HOLDINGS & FINANCE, TETRA LAVAL HOLDINGS & FINANCE SA
Application year: 1994
Main classification: B65B43
IPC codes: B65B25, B31B1, B65B43